phenobarbital improves toxicity of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Check. CYP3A4 inducers may raise the metabolism of ifosfamide to its Energetic alkylating metabolites.Steer clear of; coadministration with CYP3A inducers may well result in lowered plasma concentrations of elvitegravir and/or maybe a